Moved the User Name expansion over to FileSpec, and converted it to use getpwname directly.   Changed the file completion to deal with this, and FileSpec::Resolve now resolves all user names (not just ~/).
Moved the User Name expansion over to FileSpec, and converted it to use getpwname directly.  
Changed the file completion to deal with this, and FileSpec::Resolve now resolves all user names (not just ~/).

git-svn-id: b33bab8abb5b18c12ee100cd7761ab452d00b2b0@107370 91177308-0d34-0410-b5e6-96231b3b80d8

apple/swift-lldb,apple/swift-lldb,llvm-mirror/lldb,apple/swift-lldb,llvm-mirror/lldb,apple/swift-lldb,apple/swift-lldb,llvm-mirror/lldb,llvm-mirror/lldb,apple/swift-lldb,llvm-mirror/lldb